first of all you need to find out what exactly happens during that time. It's quite likely that the AEM instance is kind of busy and therefor cannot respond to the requests forwarded by the dispatcher, so the connections stay open and cannot be closed/reused. In that case you need to analyze your AEM and find exactly what happens. Allowing the dispatcher to send more requests to AEM doesn't help.
first of all you need to find out what exactly happens during that time. It's quite likely that the AEM instance is kind of busy and therefor cannot respond to the requests forwarded by the dispatcher, so the connections stay open and cannot be closed/reused. In that case you need to analyze your AEM and find exactly what happens. Allowing the dispatcher to send more requests to AEM doesn't help.